The present disclosure relates to an image forming apparatus preferably applied in a copying machine or a printer or the like.
The image forming apparatus includes a conveyance path for conveying a sheet to an image forming part. Then, the image forming apparatus includes a mechanism for removing (unjamming) a sheet jammed within the conveyance path.
For instance, the image forming apparatus includes an opening/closing cover turnably supported on a side surface of an apparatus body of the image forming apparatus, a sheet conveyance guide member turnably supported within the apparatus body, a lock mechanism for locking the opening/closing cover and the sheet conveyance guide member to the apparatus body. The lock mechanism includes a first lock lever provided turnably to the opening/closing cover and a second lock lever provided turnably to the sheet conveyance guide member. The first lock lever is locked by a first locking member of the apparatus body. The second lock lever is locked by a second locking member of the apparatus body. The opening/closing cover is provided with an unlocking member integrally formed with the first lock lever on an outer surface thereof. When the unlocking member (the first lock lever) is turned in an unlocking direction, the second lock lever also turns in the unlocking direction through a moving member.
A secondary transfer roller is rotatably supported by the sheet conveyance guide member described above. The secondary transfer roller is in pressure contact with a driving roller around which a transfer belt is wrapped. Accordingly, the second lock lever has to be locked by the second locking member by a force exceeding a reaction force acting on the secondary transfer roller. However, if the second lock lever is strongly locked to the second locking member, a very large force is required to turn the unlocking member. Due to that, it is unable to readily open the opening/closing cover and the sheet conveyance guide member, causing such a problem that operability in performing an unjamming process drops.
Still further, the unlocking member, the two lock levers and the moving member are combined in a complex manner so that they interlock with each other in the lock mechanism described above. Due to that, it is difficult to reduce a manufacturing cost of the lock mechanism.